This invention relates to a still video camera, particularly to a circuit for the still video camera with capability for reproducing and displaying a plurality of pictures on one screen by using a multi-screen memory.
In general, the still video camera stores pictured still images of subjects in a memory and reproduces the images. The stored images are printed by a video printer, or displayed on a monitor. A floppy disc is used as a memory element.
FIG. 1 represents the circuit of a conventional still video camera which includes a image sensor for converting an image signal of a subject received through lens into an electric signal, a signal processing unit for dividing the electric signal from the image sensor into chrominance signals of red (R), green (G), and blue (B) and a luminance signal, a camera controller for controlling camera functions according to signal selection of first and second switches for functioning to selectively display a desired screen and the next screen or to erase the present screen, a reproducer controller for controlling the display modes according to a function selection of the second switch, a mechanical controller for controlling mechanical operation of the camera, connected to the camera controller and the reproducer controller via bus lines, a floppy disc driver being driven by the mechanical controller, a motor driving unit controlled by the mechanical controller, an erasing unit for generating a screen erasing signal for the floppy disc driver, controlled by the mechanical controller, a modulator for frequency modulating the output from the signal processing unit, a recording/reproducing amplifier for mixing, switching and amplifying the chrominance signal and the luminance signal generated from the modulator in case of recording, and for amplifying the image signal read through a head of the floppy disc driver in case of reproducing, an automatic gain controller (hereinafter, referred to as AGC) for radio frequency signal processing the image signal recorded in the floppy disc driver through the recording/reproducing amplifier in case of reproducing, a demodulator for demodulating the output from the AGC, an encoder for generating a video signal by mixing the chrominance signal and the luminance signal respectively demodulated through the demodulator and then converting the signals into R, G, B signals, a timing generator for controlling the image sensor depending upon state of the camera controller, and a synchronizing signal generator for controlling the signal processing unit and the timing generator.
The operation of the circuit as shown in FIG. 1 will be described hereinbelow. When the user picks up a object and chooses the first switch 10, the camera controller 12 generates control signals for photographing. The control signals generated from the camera controller 12 are applied to the timing generator 20 and the mechanical controller 28. The synchronizing signal generator 18 supplies the timing generator 20 and the signal processing unit 16 with vertical and horizontal synchronizing signals. The timing generator 20 provided with the synchronizing signal and the timing control signal, supplies a clock signal synchronized with the vertical and horizontal synchronizing signals according to the timing control signal, to the image sensor 14 having CCD. The image sensor 14 provided with the clock signal photographs the object and converts the image signals into the electric image signals, which are applied to the signal processing unit 16. The signal processing unit 16 divides the image signal into the chrominance and the luminance signals. The modulator 22 frequency modulates and low-pass filters the chrominance and luminance signals generated from the signal processing unit 16. The recording/reproducing amplifier 24 receiving the outputs of the modulator 22 mixes, switches and amplifies the signals, which are supplied to the floppy disc driver 26 in the recording mode. In reproduction mode, the recording/reproduced amplifier 24 amplifies the reproducing signal from the floppy disc driver 26 and applies the reproduced signal to the AGC 34.
The mechanical controller 28, operating in accordance with the recording control signal and the reproducing control signal, controls the motor driving unit 32 in order to record the image data or read the recorded data in the floppy disc driver 26 depending on the control signals. Moreover, the mechanical controller 28 controls the erasing unit 30 which performs an erasing function, according to the control of the camera controller 12. The reproducer controller 38, operating according to the selection of the second switch, supplies the reproducing control signal to the mechanical controller 26 which controls the motor driving unit 32 in response to the reproducing control signal. The still video data stored in the floppy disc is applied to the recording/reproducing amplifier 24. That is, the image signals from the image sensor 14 according to the control of the camera controller 12 are recorded in the floppy disc driver 26, and the recorded image signals are read from the floppy disc driver 26 according to the control of the reproducer controller 38.
When the reproduced image signals are supplied to the AGC 34 according to the above-described operations, the chrominance signal and the luminance signal are radio frequency signal processed and gain and amplification controlled in the AGC 34.
The demodulator 40 demodulates the chrominance signal and the luminance signal which are gain controlled by the AGC 34 and supplied to the encoder 42. The encoder 42 generates the composite signals by encoding the demodulated chrominance and luminance signals according to the pulses from the pulse generator 44. That is, the data of one still screen is generated from the encoder 42.
However, the conventional still video camera illustrated in FIG. 1 reproduces the image signals recorded in the floppy disc by one screen in case of reproduction. Explaining in detail, since the floppy disc has 50 tracks, fifty screens are recorded in case of field recording, and twenty five screens are recorded in case of frame recording. That is, one track has one screen of data in case of field recording, while two tracks have one screen of data in case of frame recording. In general, only the data recorded in one track is displayed on the one screen, so that one screen of data can be reproduced.